Conventionally, a vibration actuator is known as a vibration generation source for notifying a user of incoming and the like of a mobile information terminal such as a mobile phone, or as a vibration generation source for transmitting, to a finger, a hand, a foot and the like, an operation touch of a touch panel and/or realism of a game apparatus such as a controller of a game machine (see, for example, PTLS 1 to 3).
The vibration actuator disclosed in PTL 1 is formed in a plate shape for the purpose of downsizing. The vibration actuator disclosed in PTL 1 has a flat plate shape in which a movable part is slidably supported with a shaft.
The vibration actuator disclosed in PTL 2 includes a stator including a coil and a housing, and a movable member including a magnet and a spindle disposed in the housing. In the vibration actuator disclosed in PTL 2, with the coil and the magnet, the movable member that is slidable with respect to the shaft linearly vibrates in the vibration direction with respect to the stator. The coil is wound around the movable part including the magnet.
In addition, PTL 3 discloses a VCM (Voice Coil Motor) actuator including an opposite flat coil and a flat magnet disposed above the flat coil.
Each of the movable members in the above-mentioned vibration actuators is slidably provided to the shaft, and elastically supported with the spring so as to be able to vibrate in the vibration direction. In VCM vibration actuators, no magnetic attractive force acts in a normal state because of their magnetic circuit configurations. In view of this, the movable part is elastically held mainly by the metal spring. In addition, it is known to mount the above-mentioned vibration actuators in the ring-shaped input device disclosed in PTL 4, which has a vibration communication function, for example.